{"id":"CVE-2025-38525","summary":"rxrpc: Fix irq-disabled in local_bh_enable()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: Fix irq-disabled in local_bh_enable()\n\nThe rxrpc_assess_MTU_size() function calls down into the IP layer to find\nout the MTU size for a route.  When accepting an incoming call, this is\ncalled from rxrpc_new_incoming_call() which holds interrupts disabled\nacross the code that calls down to it.  Unfortunately, the IP layer uses\nlocal_bh_enable() which, config dependent, throws a warning if IRQs are\nenabled:\n\nWARNING: CPU: 1 PID: 5544 at kernel/softirq.c:387 __local_bh_enable_ip+0x43/0xd0\n...\nRIP: 0010:__local_bh_enable_ip+0x43/0xd0\n...\nCall Trace:\n \u003cTASK\u003e\n rt_cache_route+0x7e/0xa0\n rt_set_nexthop.isra.0+0x3b3/0x3f0\n __mkroute_output+0x43a/0x460\n ip_route_output_key_hash+0xf7/0x140\n ip_route_output_flow+0x1b/0x90\n rxrpc_assess_MTU_size.isra.0+0x2a0/0x590\n rxrpc_new_incoming_peer+0x46/0x120\n rxrpc_alloc_incoming_call+0x1b1/0x400\n rxrpc_new_incoming_call+0x1da/0x5e0\n rxrpc_input_packet+0x827/0x900\n rxrpc_io_thread+0x403/0xb60\n kthread+0x2f7/0x310\n ret_from_fork+0x2a/0x230\n ret_from_fork_asm+0x1a/0x30\n...\nhardirqs last  enabled at (23): _raw_spin_unlock_irq+0x24/0x50\nhardirqs last disabled at (24): _raw_read_lock_irq+0x17/0x70\nsoftirqs last  enabled at (0): copy_process+0xc61/0x2730\nsoftirqs last disabled at (25): rt_add_uncached_list+0x3c/0x90\n\nFix this by moving the call to rxrpc_assess_MTU_size() out of\nrxrpc_init_peer() and further up the stack where it can be done without\ninterrupts disabled.\n\nIt shouldn't be a problem for rxrpc_new_incoming_call() to do it after the\nlocks are dropped as pmtud is going to be performed by the I/O thread - and\nwe're in the I/O thread at this point.","modified":"2026-04-02T12:48:01.163930Z","published":"2025-08-16T11:12:19.191Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/38xxx/CVE-2025-38525.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/2029f21f10dedb88c0f86abffcf8d6c21dcf6040"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e4d2878369d590bf8455e3678a644e503172eafa"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/38xxx/CVE-2025-38525.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-38525"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"a2ea9a9072607c2fd6442bd1ffb4dbdbf882aed7"},{"fixed":"2029f21f10dedb88c0f86abffcf8d6c21dcf6040"},{"fixed":"e4d2878369d590bf8455e3678a644e503172eafa"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-38525.json"}}],"schema_version":"1.7.5"}